Design, Tuning and Experimental Validation of Switched Fractional Order PID Controllers for an Inverted Pendulum System

This paper presents the design, implementation, and experimental validation of a switched SW FOPID-PID controller for the stabilization of an inverted pendulum (InvP) system. Additional PID and Fractional Order PID (FOPID) controllers were also designed, tuned and validated for comparison purposes. The controllers were tuned offline using Particle Swarm Optimization (PSO) and a mathematical model of the system for simulation. Their performance was assessed through key indicators, including ITAE, ISI, settling time, peak values, and variance, and compared against a manufacturer-provided PID controller. Experimental results demonstrated that all three designed controllers outperformed the manufacturer’s PID under nominal conditions. The SW FOPID-PID controller achieved the best overall performance, balancing control energy efficiency and response quality. Under external disturbances, the FOPID and SW FOPID-PID controllers exhibited superior robustness, being the switched controller the most effective, responding quickly to disturbances while minimizing positional and angular errors.